CN109563759B

CN109563759B - Compact side-feed inlet port for reductant dosing unit

Info

Publication number: CN109563759B
Application number: CN201780050557.8A
Authority: CN
Inventors: R.W.麦克法兰
Original assignee: Continental Automotive Systems Inc
Current assignee: Vitesco Technologies USA LLC
Priority date: 2016-08-18
Filing date: 2017-08-18
Publication date: 2021-10-29
Anticipated expiration: 2037-08-18
Also published as: JP6743285B2; EP3500741A1; EP3500741B1; US10774719B2; WO2018035439A1; KR20190026920A; US20180051613A1; JP2019527796A; CN109563759A; KR102186649B1

Abstract

A side-feed inlet port for an injector that utilizes stamped components to form a compact, high strength, three-piece inlet port at significantly reduced cost. By using an inner sleeve and an outer sleeve, the injector seal is completed using the inner sleeve, creating a sealing point while allowing the entry conduit to attach to the outer sleeve at, above, or below the DEF injector's sealing point. The configuration of the inlet port is such that there is a proper seal between the inner sleeve and the one or more seals, while allowing for a connection between the inlet conduit and the outer sleeve to reduce the overall height of the inlet port, and therefore, the injector. The location of the access conduit can be varied without affecting the sealed connection between the inner sleeve and the seal so that the desired overall height can be achieved.

Description

Compact side-feed inlet port for reductant dosing unit

Technical Field

The present invention relates generally to a side-feed inlet port for a reductant delivery unit used as part of a selective catalytic reduction system for an exhaust aftertreatment system.

Background

New emissions regulations in europe and north america are driving the implementation of new exhaust aftertreatment systems, particularly for lean-burn technologies such as compression-ignition (diesel) engines and stratified-charge (spark-ignition) engines operating at lean and ultra-lean conditions, often with direct injection. Lean-burn engines exhibit high levels of nitrogen oxide emissions (NO)_x) It is difficult to handle in an oxygen-rich exhaust environment, which is characteristic of lean-burn combustion. The treatment of NO under these conditions is currently being developed_xThe exhaust gas aftertreatment technique of (1).

One of these techniques includes promoting ammonia (NH)₃) With Nitrogen Oxides (NO) of the exhaust gases_x) React to produce nitrogen (N)₂) And water (H)₂O) is used as the catalyst. This technique is known as Selective Catalytic Reduction (SCR).Ammonia is difficult to handle in its pure form in the automotive environment, so these systems are habitually using a liquid aqueous urea solution, usually urea (CO (NH)₂）₂) The concentration of (2) is 32%. This solution is known as AUS-32 or Diesel Exhaust Fluid (DEF) and is also known under its commercial name AdBlue. DEF is delivered to the hot exhaust stream and converted to ammonia in the exhaust gas after undergoing pyrolysis or to ammonia and isocyanic acid (HNCO) after undergoing thermal decomposition. The isocyanic acid is then hydrolyzed with water present in the exhaust gas and converted into ammonia and carbon dioxide (CO)₂) The ammonia produced by pyrolysis and hydrolysis then undergoes a catalytic reaction with the nitrogen oxides as previously described.

Delivery of DEF solution to the exhaust involves precise metering of DEF and proper preparation of DEF to facilitate later mixing of ammonia in the exhaust stream. Delivery of DEF into the exhaust is typically accomplished using some type of injector. In a Reductant Delivery Unit (RDU), an injector is surrounded by a metal housing. The housing is used to protect the injector and to provide a mounting system for the exhaust pipe and to provide a hydraulic connection interface for the injector. As the demand for vehicles to become more efficient and to include more features and capabilities increases, packaging limitations become increasingly restrictive.

Thus, there is a need for a sprayer that allows for greater flexibility in packaging so that the sprayer can be installed in a variety of locations while following more stringent packaging requirements.

Disclosure of Invention

In one embodiment, the present invention is a side-feed inlet port for an injector that utilizes three stamped components such that the side-feed inlet port is compact, high strength, and manufactured at significantly reduced cost. Sealing of the injector is accomplished using an inner sleeve, forming a sealing point, by using an inner sleeve and an outer sleeve (both made of stamped metal), while allowing the entry conduit to be attached to the outer sleeve at or below the DEF injector's sealing point. The injector has one or more seals and the configuration of the inlet port is such that there is a suitable seal between the inner sleeve and the seals, while allowing for a connection between the inlet conduit and the outer sleeve to reduce the overall height of the inlet port and, therefore, the overall height of the injector. The location of the access conduit can be varied without affecting the sealed connection between the inner sleeve and the seal so that the desired overall height can be achieved. The assembly is completed by brazing or welding the parts together, providing a robust, compact and low cost access port.

One advantage of the present invention is that the total internal fluid volume in the access port is reduced. For RDUs that require fluid to be purged when the engine is shut down (to mitigate the possibility of freezing and subsequent damage to the fluid injectors), a smaller volume of liquid in the inlet port equates to a shorter purge time. As a stamped component, the outer sleeve may have various shapes, such as different volume reduction features, to further reduce the volume of the interior.

In one embodiment, the present invention is an access port for an injector having an inner sleeve mounted to an access tube of the injector, and an outer sleeve, wherein the inner sleeve is partially disposed within the outer sleeve. The cavity is formed as part of the outer sleeve such that the inner sleeve is partially disposed in the cavity. The aperture is formed as part of the outer sleeve such that the aperture is in fluid communication with the cavity. The access conduit is partially disposed in the aperture such that the access conduit is in fluid communication with the cavity. During operation of the injector, fluid flows through the inlet conduit and into the cavity, and from the cavity into the inlet tube.

When assembled, a portion of the inner sleeve blocks the aperture and a portion of the aperture not blocked by the sleeve forms a flow path. DEF flows from the inlet conduit, through the flow path and into the cavity, and then into the inlet tube.

In one embodiment, the outer sleeve, the inner sleeve, and the access tube are all formed using a stamping process or a forming process, which reduces the cost of manufacturing the access port.

In one embodiment, the injector includes a volume reduction feature that is used to reduce the total volume of the cavity of the outer sleeve. In one embodiment, the volume reduction feature is a hemispherical wall portion formed as part of the outer sleeve. The upper wall is formed as part of the outer sleeve and, in one embodiment, the volume reduction feature is formed as part of the upper wall of the outer sleeve.

Reducing the volume in the cavity reduces the amount of DEF in the cavity, and thus the total amount of DEF in the injector. Reducing the total volume of DEF in the injector reduces the total volume of DEF expanding as it freezes. Less volumetric expansion of the DEF results in less strain on the injector components.

For injectors equipped with a purge function, where DEF is purged from the injector under certain conditions, such as when the vehicle is turned off. Having a volume reduction feature results in less total DEF in the injector, and therefore less DEF needs to be purged. Additionally, when conditions arise where the injector must be used, and the injector must be "primed," DEF is pumped back into the injector. Having a smaller volume results in less DEF being required to fully prime the injector.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Drawings

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is an exploded view of a portion of an exhaust system having an injector according to an embodiment of the invention;

FIG. 2 is a side view of an injector having a compact side-feed inlet port according to an embodiment of the invention;

FIG. 3 is an enlarged cross-sectional view of a compact side-feed inlet port mounted to an injector according to an embodiment of the invention;

FIG. 4 is an enlarged cross-sectional view of an alternative embodiment of a compact side-feed inlet port mounted to an injector according to an embodiment of the invention;

FIG. 5 is a perspective view of an alternative embodiment of a compact side-feed inlet port mounted to an injector according to an embodiment of the invention; and

FIG. 6 is an exploded view of an alternative embodiment of a compact side-feed inlet port mounted to an injector according to an embodiment of the present invention.

Detailed Description

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

An injector having a side-feed inlet port in accordance with the present invention is shown generally at 10 in fig. 1-3. The injector 10 has a multi-piece inlet port, shown generally at 12, that receives Diesel Exhaust Fluid (DEF). The inlet port 12 is connected to a hydraulic connector 62, which hydraulic connector 62 is connected to a hose 64 such that DEF is transferred from the hose 64 to the inlet port 12. The injector 10 also includes an inlet tube 14, where DEF can flow from the inlet port 12 and into the inlet tube 14. In addition, the injector 10 also includes an actuator, such as a solenoid (not shown), that is used to control a valve assembly (not shown) to control the flow of DEF into the exhaust pipe 16. The exhaust duct 16 includes an outer mounting portion 18, the injector 10 being mounted to the outer mounting portion 18.

Surrounding the inlet tube 14 is a first seal, which in this embodiment is an O-ring 20. The injector 10 also includes a housing 22, the housing 22 surrounding a portion of the inlet pipe 14. The housing 22 includes a groove 24 and a second seal, which in this embodiment is another O-ring 26, is disposed in the groove 24.

The access port 12 includes several parts; one of the parts is an inner sleeve 28. The inner sleeve 28 is generally cylindrical in shape and has a flange portion 30. When the injector 10 is assembled, the inner sleeve 28 surrounds both O-

rings

20, 26, which provides a sealing function to prevent DEF from migrating around the O-

rings

20, 26 into certain areas of the injector 10. The inner sleeve 28 also includes an aperture 28a through which DEF passes before entering the inlet tube 14.

Access port 12 also includes an outer sleeve 32, which outer sleeve 32 is also cylindrical in shape and includes a cavity, generally shown at 34. The outer sleeve 32 surrounds the inner sleeve 28 as shown in fig. 3. The inner sleeve 28 may be press fit into the outer sleeve 32 or the inner sleeve 28 may be connected to the outer sleeve 32 along the fused connection points 36, 38 using a fused connection. The inner sleeve 28 and the outer sleeve 32 may also be joined together by a brazing process. The outer sleeve 32 also includes a cylindrical flange portion 40 having an aperture 42. The entry conduit 44 is partially disposed in the aperture 42 such that the entry conduit 44 is connected to the outer sleeve 32. The inlet conduit 44 may be disposed in the aperture 42 by a welded connection, a press-fit connection, or the like. The inlet conduit 44 is connected to the hydraulic connector 62 to receive DEF from the hose 64.

The inner sleeve 28 includes a circumferential wall 46, and a portion of the circumferential wall 46 blocks a portion of the apertures 42. The portion of the aperture 42 that is not blocked provides a flow path, shown generally at 48. The inlet conduit 44 also includes an inlet aperture 50, and DEF flowing into the inlet aperture 50 and through the inlet conduit 44 flows through the flow path 48 and into the cavity 34 of the outer sleeve 32. The DEF then flows from the cavity 34 into the inlet tube 14.

An area of the first O-ring 20 contacts the circumferential wall 46 of the outer sleeve 32, forming a sealing area, shown generally at 56. The size of the sealing area 56 can vary depending on the size of the O-ring 20 and how much the O-ring 20 is compressed, resulting in a greater or lesser amount of the outer surface of the O-ring 20 contacting the circumferential wall 46. The sealing region 56 has a center 56a and the entry conduit 44 has an axis 58 along the center of the entry conduit 44, as shown in fig. 3. The axis 58 is positioned at a distance 60 from the center 56a of the sealing region 56. The distance 60 may vary to affect the size of the flow path 48. The size of the flow path 48 may also be affected by changing the diameter of the inlet conduit 44 and correspondingly changing the diameter of the cylindrical flange portion 40, changing the position of the outer sleeve 32 relative to the inner sleeve 28, and changing the position of the cylindrical flange portion 40 relative to the outer sleeve 32. In this embodiment, the center 56a of the sealing area 56 is below the axis 58. However, it is within the scope of the present disclosure that the location and size of any of the above-described components may be varied such that the center 56a of the sealing region 56 may be any distance 60 above or below the axis 58.

Each of the inner sleeve 28, outer sleeve 32, and access conduit 44 are made by a stamping process and then assembled together during manufacture.

An alternative embodiment of the present invention is shown in fig. 4-6. In this embodiment, the outer sleeve 32 also includes a volume reduction feature 52, which volume reduction feature 52 is a hemispherical wall portion in this embodiment. The volume reduction feature 52 is formed as part of an upper wall 54 of the outer sleeve 32. The volume reduction feature 52 reduces the total volume in the cavity 34 of the outer sleeve 32. In this embodiment, the volume reduction feature 52 has a radius of about six millimeters, and the shape of the volume reduction feature 52 reduces the volume of the cavity 34 by about 20%. However, it is within the scope of the present invention that other sizes and shapes may be used to form the volume reduction feature 52 to vary the volume of the cavity 34. Reducing the volume in the cavity 34 reduces the amount of DEF in the cavity 34, and thus the overall amount of DEF in the injector 10. Under certain conditions, DEF may freeze when exposed to low temperatures. When the vehicle is shut down, some systems do not have the ability to purge DEF, and DEF may freeze (and expand) when exposed to low temperatures. Reducing the total volume of DEF in the injector 10 reduces the total volume expansion of DEF when it freezes. The smaller volumetric expansion of the DEF results in less strain on the parts of the injector 10.

There are some injectors with purge function. The injector 10 of the present invention may be equipped with this purge function, wherein DEF is purged from the injector 10 under certain conditions, such as when the vehicle is turned off. Having the volume reduction feature 52 results in less total DEF in the injector 10, and therefore less DEF needs to be purged. Additionally, when conditions arise in which the injector 10 must be used, and the injector 10 must be "primed" (where DEF is pumped back into the injector 10), the smaller volume results in less DEF being required to fully prime the injector 10.

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Claims

1. An ejector, comprising:

an inlet port for delivering fluid to an inlet tube;

an inner sleeve that is part of the access port;

an outer sleeve mounted to the inner sleeve, the outer sleeve being part of the access port; and

an entry conduit partially disposed in the outer sleeve, the entry conduit being part of the entry port;

wherein fluid flows from the entry conduit through the outer sleeve and into the entry tube,

wherein a seal is disposed between the inner sleeve and the access tube to form a sealed region, and

wherein the entry conduit is attached to the outer sleeve at or below the sealing region.

2. The injector of claim 1, further comprising:

an aperture formed as part of the outer sleeve;

wherein a portion of an access conduit is disposed in the aperture formed as part of the outer sleeve and the access conduit is in fluid communication with a cavity.

3. The injector of claim 2, further comprising:

a flow path;

wherein a portion of the inner sleeve blocks the aperture and the flow path is formed by the portion of the aperture not blocked by the inner sleeve.

4. The injector of claim 1, further comprising:

a cavity formed as part of the outer sleeve;

wherein fluid flows from the entry conduit into the cavity and then into the entry tube.

5. The injector of claim 4, further comprising a volume reduction feature, wherein the volume reduction feature reduces a volume in the cavity formed as part of the outer sleeve.

6. The injector of claim 5, the volume reduction feature further comprising a hemispherical wall portion formed as part of the outer sleeve.

7. The injector of claim 5, further comprising:

an upper wall formed as part of the outer sleeve;

wherein the volume reduction feature is formed as part of the upper wall of the outer sleeve.

8. The injector of claim 1, wherein the outer sleeve, the inner sleeve, and the inlet tube are all separate pieces formed using one process selected from the group consisting of a stamping process and a forming process.

9. An inlet port for an injector, comprising:

an inner sleeve mounted to an inlet tube of an injector;

an outer sleeve, the inner sleeve partially disposed in the outer sleeve;

a cavity formed as part of the outer sleeve, the inner sleeve being partially disposed in the cavity;

an aperture formed as part of the outer sleeve, the aperture being in fluid communication with the cavity; and

an entry conduit partially disposed in the aperture such that the entry conduit is in fluid communication with the cavity;

wherein fluid flows through the entry conduit and into the cavity, and from the cavity into the entry tube,

10. The access port as defined in claim 9, further comprising:

a flow path through which the inlet conduit is in fluid communication with the cavity;

11. The access port as defined in claim 9, wherein the outer sleeve, the inner sleeve, and the access tube are all formed using one process selected from the group consisting of a stamping process and a forming process.

12. The access port as defined in claim 9, further comprising a volume reduction feature, wherein the volume reduction feature reduces a volume in the cavity formed as part of the outer sleeve.

13. The access port as defined in claim 12, the volume reduction feature further comprising a hemispherical wall portion formed as part of the outer sleeve.

14. The access port as defined in claim 12, further comprising:

an upper wall formed as part of the outer sleeve;